The present Applicant has previously described a plethora of printers having replaceable printheads. Replaceable printheads typically comprise an ink manifold having one or more of printhead chips mounted thereto. Printheads may be shipped either ‘wet’ or ‘dry’ for installation by users. Usually, printheads are shipped ‘wet’ to avoid potential problems with priming during installation. Wet-shipped printheads may be filled with either ink or a shipping fluid, which is typically an ink vehicle lacking any colorant.
However, wet-shipped printheads are less convenient for users, because ink or shipping fluid leak from the printhead during shipment and/or spill during the installation process. Users would prefer to receive dry printheads, which are not prone to leaking or spilling fluids during shipment or installation.
Dry-shipped printheads are feasible for printers equipped with a suitable ink delivery system capable of priming a dry printhead. The Applicant has disclosed a number of ink delivery systems suitable for priming printheads with ink when installed (see, for example, U.S. Pat. No. 8,845,083, the contents of which are incorporated herein by reference).
However, additional problems are associated with shipment of dry printheads. It has been observed by the present inventors that dry-shipped printheads exhibit a significantly higher number of dead nozzles than wet-shipped printheads. Investigations have shown that there is a tendency for glue joints, potting material and other polymers in the printheads to leach or outgas organic material into ink pathways e.g. by virtue of temperature fluctuations during storage. Organic leachants or volatile organic compounds (“VOCs”) are particularly problematic when they reach pinch points in the ink pathway e.g. nozzle chamber inlets, baffle holes, nozzle openings etc. In a dry-shipped printhead, the leachants may bridge across these pinch points and form a viscous plug, which cannot be removed by subsequent priming of the printhead. Accordingly, this leaching process is believed to be responsible for a high number of unrecoverable dead nozzles in dry-shipped printheads compared to those shipped wet.
It would therefore be desirable to provide a method for dry shipment of printheads, which minimizes a number of dead nozzles in the printhead.